Celsius to Fahrenheit: Formula and Quick Tricks

Both formulas, the double-plus-30 shortcut, and the reference points worth memorizing.

Recipes, weather and thermostats keep forcing this conversion. Here's everything you need.

The formulas

°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9

Example: 25°C → (25 × 1.8) + 32 = 77°F.

The mental shortcut

Double it and add 30. 20°C → 40 + 30 = 70°F (actual: 68°F). It's within a couple of degrees — fine for weather and cooking estimates.

Reference points worth memorizing

1. 0°C = 32°F (freezing)
2. 20°C = 68°F (room temperature)
3. 37°C = 98.6°F (body temperature)
4. 100°C = 212°F (boiling)

For oven temperatures and anything precise, use the converter above — exact to the decimal.